What about compound data structures? Well, there are several
possible approaches to this. Say, we have a 1:n relationship
between the Jedi above and a Fighter
(i.e., each Jedi owns a number of fighter spacecraft). The
Fighter class is described in the database with the
following data.

In other words, Luke owns two Fighters (an X- and a B-Wing) and
Yoda owns a Star Destroyer, while Obi Wan is dead--sort of,
anyway.

Again, this relationship between the data can be modeled in the
OO domain in several ways. We'll just pick one that seems most
obvious and skip the others. So we'll want the Jedi
class to have a member that is a collection of Fighter
objects. Here is the class Fighter set up for use with
Amber.